Information Processing in the Visual Systems of Arthropods


Book Description

It is now generally accepted for a variety of reasons - morphological as well as physiologica- that the visual systems of arthropods provide a suitable model for the study of information proces sing in neuronal networks. Unlike the neurophysiology of the visual pathway in the frog and the cat which is more than adequately documented, recent work on the compound eye and optical ganglia of spiders, crustaceans, and insects has scarcely been summarized. In order to fill this void so that others, especially vertebrate neurophysiologists may become familiar with the advan tages of these systems, our group at Zurich University organized here in March 1972, a European meeting to discuss the anatomical. ! neurophysiological and behavioral knowledge on the compound eye and the visual. pathway of arthropods. Systems analysis was regarded as the main theme of the conference, but systems analysis of a network of neurons cannot be done as a mere "black-box" maneuver. The conference therefore tried to reconcile neurophysiology and behavioral analysis in order to make predictions about a necessary and sufficient neural structure. The "wiring dia grams" of such a structure might then be confirmed histologically. Hence the aim of the conferen ce was not to deal only with the structure and function of the compound eye - i. e.



















Arthropod Brains


Book Description

In The Descent of Man, Charles Darwin proposed that an ant’s brain, no larger than a pin’s head, must be sophisticated to accomplish all that it does. Yet today many people still find it surprising that insects and other arthropods show behaviors that are much more complex than innate reflexes. They are products of versatile brains which, in a sense, think. Fascinating in their own right, arthropods provide fundamental insights into how brains process and organize sensory information to produce learning, strategizing, cooperation, and sociality. Nicholas Strausfeld elucidates the evolution of this knowledge, beginning with nineteenth-century debates about how similar arthropod brains were to vertebrate brains. This exchange, he shows, had a profound and far-reaching impact on attitudes toward evolution and animal origins. Many renowned scientists, including Sigmund Freud, cut their professional teeth studying arthropod nervous systems. The greatest neuroanatomist of them all, Santiago Ramón y Cajal—founder of the neuron doctrine—was awed by similarities between insect and mammalian brains. Writing in a style that will appeal to a broad readership, Strausfeld weaves anatomical observations with evidence from molecular biology, neuroethology, cladistics, and the fossil record to explore the neurobiology of the largest phylum on earth—and one that is crucial to the well-being of our planet. Highly informative and richly illustrated, Arthropod Brains offers an original synthesis drawing on many fields, and a comprehensive reference that will serve biologists for years to come.







The Neurophysiology of Data Processing in the Optic Ganglia of Insect Compound Eyes


Book Description

The report covers results of studies of neural information processing in the compound-eye visual systems of insects subject to a restricted class of visual object stimuli. In the first phase of the research, the behavior of single visual units in the optic lobes of Romalea were described and categorized. Eight types of operation on visual objects were defined. Similar operations were observed in single visual units in the optic lobes of Locusta and Schistocerca. In the second phase of the study, spatial resolution was examined for a variety of classes of visual unit in the locust. The anomalous 0.3 degree resolution of the VNC giant fiber was verified for spot checkerboard stimuli, as well as a radial grating. The 'edge effect' for the radial grating was seen to give enhanced response with the mask when max. stripe period was above a certain limit, and to be spoiled by the mask when below the limit. The resolution of vector units in the 3rd cervical nerve was tested, and found to follow Nyquist theory. Results suggested that a 2-mode-system may exist in insect vision: one to measure, without regard to form, local changes in light intensity over the eye; the other responding to object form-in-motion. The latter system is subject to the constraints of spatial sampling theory. (Author).




Development of the Visual System


Book Description

Development of the Visual System presents a selection of current studies that clearly illustrate principles of visual system development. These range from retinal development in fish and frogs to the effects of abnormal visual experience on the primary visual cortex of the cat. The book is unique in addressing four specific and fundamental aspects of development: cell lineage and cell fate, specificity and targeting of axons, specification of visual cortex, and correlates of the critical period. Encompassing technical advances in cellular and molecular biology and in video imaging and microscopy, contributions in each of these areas provide new information at the cellular and molecular levels to complement the now classic descriptions of visual development previously available at the level of neural systems.ContributorsKaren L. Allendoerfer, David M. Altshuler, Antonella Antonini, Seymour Benzer, Edward M. Callaway, Constance L. Cepko, Hollis T. Cline, Max S. Cynader, N. W. Daw, Scott E. Fraser, K. Fox, Eckhard Friauf, Anirvan Ghosh, R. W. Guillery, William A. Harris, Christine E. Holt, Lawrence C. Katz, Susan McConnell, Pamela A. Raymond, Thomas A. Reh, Carla J. Shatz, Michael P. Stryker, Claudia A. 0. Stuermer, Mriganka Sur, David L. Turner, T. N. Wiesel